FOXP3 and obesity due to melanocortin 4 receptor deficiency: Consistent with a pathogenic role, our studies in Foxp3RFP/GFP mice show that HFD feeding consistently induced VAT accumulation of YFP+Foxp3- cells, although with inter-individual variability that closely correlates with obesity-related symptoms, including increased body weight and adipose tissue mass (Figure 1H), implicating these cells in disease progression.